Looking for fics where Spike and/or Buffy is a criminal. AH, of course. One of them can be undercover agents or with law enforcement to investigate the other. Both can be criminals. Thief, assassin, con artist, all are game.
The ones I've read so far are:
Criminal Game by Ashlee
Summary: William 'Spike' Reed is the most successful art thief on record- and he's never been caught. As one of the most powerful men in the country, he has managed to elude arrest for years while still maintaining a prominent status. When FBI Agent Buffy Summers is assigned to go undercover to capture him, she's entered a game that she's not sure she can win.
Crystal by Vanilla
A beautiful blonde is undercover for the FBI in Los Angeles. She is working as a computer hacker for one of the country's richest, dirtiest, and most handsome businessmen, who just happens to have a few secrets of his own. Sparks fly, because don't they always?
Winner at the Spuffy Awards! Reader's choice for Best Spike Characterization and Best Fantasty Saga, Judge's Choice for Best Fantasty 'We Missed The Bed, Again', and Judge's Pick. Nominated at the Cradle of Humanity Awards for the Happy Worker Award.
Girl With Stars by Anaunthe
Summary: All Human. Sparks fly when Buffy Summers meets successful business man Spike Thorndale. Unfortunately, Spike is a suspected art thief, and it's Buffy's job to collect evidence against him. Already emotionally involved, things get worse when Buffy's evidence is used to implicate Spike in connection with three brutal murders – one in China, one in Romania, and the last in New York. ** NOMINATED AT LOVE'S LAST GLIMPSE AWARDS**
One of them must be a criminal. Not two agents working together. | 
